fix lost workspace overflow markers

As WS_Reset() clears the overflow marker, the correct order for
resetting and marking an overflow is WS_Reset(); WS_MarkOverflow();

Fixes the last seemingly obscure bit of #2645

bin/varnishd/cache/cache_vrt_var.c

@@ -411,8 +411,8 @@ VRT_l_beresp_storage_hint(VRT_CTX, const char *str, ...)
 
 	if (p == NULL) {
 		VSLb(ctx->vsl, SLT_LostHeader, "storage_hint");
-		WS_MarkOverflow(ctx->ws);
 		WS_Reset(ctx->ws, sn);
+		WS_MarkOverflow(ctx->ws);
 		return;
 	}
 

lib/libvmod_std/vmod_std.c

@@ -154,8 +154,8 @@ vmod_log(VRT_CTX, const char *fmt, ...)
 	va_end(ap);
 
 	if (p == NULL) {
-		WS_MarkOverflow(ctx->ws);
 		WS_Reset(ctx->ws, sn);
+		WS_MarkOverflow(ctx->ws);
 		return;
 	}